Small Warship Survivability

USS Hornet (CV-8) abandon ship

(USS Hornet (CV-8) as the crew abandons ship

There has been a lot of discussion lately about the survivability of the LCS and smaller combatants in general. A recent US Naval Institute News opinion piece contends,

“Small warships are historically unsurvivable in combat. They have a shorter floodable length, reduced reserve buoyancy and more likely to be affected by fire and smoke damage than larger combatants. In both World Wars, losses in ships below 3000 tons in displacement far exceeded those of larger vessels.

“In World War II, for example, the U.S. lost a total of 71 destroyers and 11 destroyer escorts — all under 3400 tons displacement and less than 400 feet in length.

“By comparison, only 23 larger ships were lost. Part of that figure is undoubtedly due to their operational employment, but in simple terms of engineering and physics, larger ships are inherently more survivable than their smaller counterparts.”

In the Coast Guard we once had a saying, “In our obscurity is our security.” I think that should be kept in mind when we consider the survivability of small surface combatants. No, they cannot take as much damage as major surface combatants, but the enemy gets a vote, and he will be less “excited” by the presence of smaller vessels, while he will normally choose to put more effort into destroying larger, more threatening ships. As in land warfare, tanks are more survivable than infantrymen, but they don’t necessarily last longer.

To look at how this factor might influence survivability, I looked at how many of the ships that were in commission at the beginning of World War II were sunk as a result of enemy action. My source is the “Summary of War Damage to U.S. Battleships, Carriers, Cruisers, Destroyers, and Destroyer Escorts” which is accessible here. The figures there do not correspond to those quoted above, rather they report 58 destroyers and 9 destroyer escorts sunk, along with 26 larger surface combatants, all listed by name. (The USNI post may have included constructive losses that were not actually sunk or losses to other than enemy action, and does not include the three battleships salvaged although they were out of action most of the war.)

If we look only at the US fleet at the beginning of the war, it included 233 major surface combatants of which 46 or 19.7% were sunk by enemy action during the course of the war. If we break it down by class it looks like this:

Type: Number in Commission, Dec. 7, 1941/Number sunk/% lost to enemy action
Aircraft Carriers (CV): 7/4/57.1%
Escort Carrier (CVE): 1/0/0%
Battleships (BB): 17/5/29.4% (of the 5 sunk, all were at Pearl Harbor, 3 were salvaged)
Heavy Cruisers (CA): 18/7/38.9%
Light Cruisers (CL): 19/1/5.3%
Destroyers (DD): 171/29/17%

(There were no Destroyer Escorts in commission at the beginning of the war.)

If we lump  all the cruisers together, 8 of 37 were lost or 21.6%

If we lump the lone escort carrier together with the fleet carriers then four of eight were sunk or 50%

Additionally three destroyers were lost to weather in a hurricane. They were not ballasted properly, because of the exigencies of impending combat operations.

Clearly, at least looking at the World War II experience, the US Navy did not loose a higher percentage of smaller ships. If anything it appears the opposite is true. A smaller percentage of smaller ships were lost (17% vs 27.4%). More small ships were lost simply because there were many more of them. Undoubtedly some of the DDs and DEs that were sunk, would have survived the damage they received, if they had been bigger, but presumably there would also have been fewer of them. If the decision criteria were an equal chance of being sunk, then probably taking greater risk with smaller ships is both reasonable and unavoidable.

I will note that the probability of personnel loss on small ships is probably higher because they are more likely to sink quickly and catastrophically, while larger ships are more likely to sink slowly.

USS_Newcomb_Damage_1945

Photo: USS Newcomb DD 586 was hit by as many as five kamikaze on 6 April 1945 as she was screening for the cruiser USS St. Louis off Okinawa. She survived but was not repaired.

I will add a bit of anecdotal evidence. As part of Operation Overlord, the Normandy Invasion, 60 US Coast Guard 83 foot patrol boats were assigned to rescue those unlucky enough to find themselves in the water or sinking. 30 went to the American beachheads and 30 went to the British and Canadian beachheads. Being wooden hulled and gasoline powered, they certainly would not have been considered “survivable.” Apparently they were in the thick of it, because they rescued 1438 men from the water and sinking craft. In spite of all the fire from shore, not a single boat was sunk and not a single crewmen was killed. Apparently the German gunners were too busy with the landing craft hitting the beach and the warships that were shelling them. They simply were not a priority target.

ResFlot1_CG21

USCG 83 ft patrol boat, probably June 1944. Photographer unknown.

16 thoughts on “Small Warship Survivability

  1. I would have to disagree with you on the battleship losses in WW2. No Battleships were sunk at Pearl Harbor. While it is true two were lost to enemy action( Arizona and Oklahoma) It is impossible for a ship the size of a battleship to be sunk in the shallow harbor of Pearl. Remember the Japanese had to use specialy modified torpedoes for the task.

    • They were sitting on the bottom. If the water depth had been greater, it would have been impossible to raise them. They were out of the war when the they would have been useful. By the time the ships that were raised and modernized and returned to service the result was no longer in doubt.

      They did not just settle a few feet. Arizona’s damage was catastrophic. Oklahoma was hit by five torpedoes and capsized. West Virginia was hit by seven torpedoes and two bombs. Even if buttoned up she would likely not have survived.

      On the other hand if California had been at GQ with the Zebra set she probably would have survived. The same for Nevada.

      You might make the argument that except for the fact that this was a surprise attack, no US battleships would have been sunk, but if you broaden your perspective Battleships and Battlecruisers in general were sunk in equal or greater proportion to smaller warships in other navies as well. The Brits lost four of 15 of their older battleships and battlecruisers, and one of four of their new ones. The Germans lost three of four in combat and disarmed and scuttled the forth. The Italians lost one of three new ships. Their four older battleships survived the war but one of them had been sunk and raised twice. Of the Japanese twelve battleships only one survived the war. Three survived until July 1945. One was destroyed by an internal explosion, but the two monsters Yamato and Musashi were destroyed by USN air attack, Musashi on her first real mission and Yamato on her second. Of the remaining five, one was sunk by a submarine and the other four went down after surface combat with US forces.

      Battleships excited the opposition and they got a lot of attention.

    • Yes, these numbers correspond to original report. As noted the differences are explainable by the fact that this report does not include the three ships raised at Pearl Harbor but does include losses to non-combat causes. I chose not to include losses of ships commissioned after Pearl Harbor because they were exposed to danger different periods of time. The first year of the war was the most dangerous by far to US ships. After 1942 the odds turned decisively in the US favor.

  2. and I might add that (other than the Vestal a PH), in WW2 there were relatively few what was then called auxiliaries lost due to enemy action. Merchants yes, catastrophic accidents yes, but sinkings due to combat, how many? Still researching that.
    Then go look at the 1980s Tanker Wars, and see how were attacked as opposed to be out of action (or mission lost).
    Point is larger hulls are harder to sink.

    • Part of the reason I really think cutters are inadequately armed for stopping merchant ships used for terrorist attacks. Tankers because of their many sealed compartments are particularly hard to sink.

      There have been some other changes since WWII that have been favorable to warship survivability. In WWII warships were heavily loaded with weapons. You can see the effect in the relatively low freeboard of ships like Fletcher class destroyers, meaning they had relatively limited reserve buoyancy. Current designs have more.

      Also they carried huge quantities of dumb ammunition that was in fact hazardous to own ship. Frequently it was the secondary effect of magazine explosions that did most of the damage. Now warships tend to carry few smart rounds.

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  4. I think a look at the quality of Damage Control training in later stages of the war, versus the steep learning curve in 1941-42 would also show that ships survived damage in 1945 that would have been considered catastrophic in earlier years.

  5. A couple of technical comments here – need to look at both the susceptibility and vulnerability components of the survivability triangle. Using the numbers from the battle damage summaries, through 1944, 45% of DEs that took reportable damage were lost. The vulnerability works out somewhere around 35% of DDs, 18% of cruisers, and 11% of battleships. Similar relationship among the carrier classes, where about 33% of CVEs reported were losses, 25% of CVLs, and 15% of CVs. (numbers from memory because the data is at home).
    The susceptibility component is where the numbers of smaller ships make a big difference. Your numbers are overstated because you don’t account for the new builds entering the fleet each year. About 30% of cruisers took damage or were lost, and were the real steady workhorses of the war. There were no significant CV or BB damage events in ’43, although they both popped back up to ’42 levels once we started driving west.
    It looks like much smaller percentages of the DDs but I ran out of time pulling together commissioning dates to bounce against the annual loss numbers.

    • If you look at what percentage of damaged ships were sunk, yes smaller ships are easier to sink. I acknowledged this, but on the other hand, because larger ships are higher priority targets they were hit more frequently. Lots of ways to work the data, but what I saw was that If we look at ships that went through the entire war, a higher percentage of the larger ships were sunk. The smaller ships could take less damage but on the other hand they were hit less often.

      • Something else I had not considered before the discussion here, not only were larger ships sunk more frequently than smaller ships, because they were also damaged much more frequently than small ships, they spent more time (on average) out of action being repaired.

    • I would never object to steps taken to improve the survivability of ships. Improve compartmentation. Provide redundant propulsion and generator capacity. But taking a position that every ship should be able to take a torpedo hit amidships and continue to fight is unrealistic.

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